The human tap nuclear RNA export factor contains a novel transportin-dependent nuclear localization signal that lacks nuclear export signal function.

Journal Article

The human Tap protein mediates the sequence-specific nuclear export of RNAs containing the constitutive transport element and is likely also critical for general mRNA export. Here, we demonstrate that a previously defined arginine-rich nuclear localization signal (NLS) present in Tap acts exclusively via the transportin import factor. Previously, transportin has been shown to mediate the nuclear import of several heterogeneous nuclear ribonucleoproteins, including heterogeneous nuclear ribonucleoprotein (hnRNP) A1, by binding to a sequence element termed M9. Although the Tap NLS and the hnRNP A1 M9 element are shown to compete for transportin binding, they show no sequence homology, and the Tap NLS does not conform to the recently defined M9 consensus. The Tap NLS also differs from M9 in that only the latter is able to act as a nuclear export signal. The Tap NLS is therefore the first member of a novel class of transportin-specific NLSs that lack nuclear export signal function.

Full Text

Duke Authors

Cited Authors

  • Truant, R; Kang, Y; Cullen, BR

Published Date

  • November 5, 1999

Published In

Volume / Issue

  • 274 / 45

Start / End Page

  • 32167 - 32171

PubMed ID

  • 10542253

International Standard Serial Number (ISSN)

  • 0021-9258

Language

  • eng

Conference Location

  • United States